pool plumbing layout review, please

[gerzak]

Hi all, I did a lot of research, and I'm finding it tough to know if I will be putting the pool plumbing components in the right order.
Any advice is greatly appreciated!

I just installed a 9-ft. by 13-ft. by 4-ft.-deep semi-inground pool with a vinyl liner.

A waterproof plumbing pad will be about 10 to 15 ft. away in a nearby shed where the floor is about 3 ft. below the water level in the pool—so all of the plumbing is slightly below the level of the top of the pool water, but above the bottom of the pool.

There is one skimmer and one return inlet on one long side of the pool, and there is another return inlet on the other long side. I'm running about 15-20 feet of 2-in. PVC from the skimmer, and I was considering running a dedicated 1.5-in. line for each of the returns.

I'm trying to figure out the best layout for all the parts in the shed, and I'm thinking the following makes sense...but let me know:

• 2 inch line from skimmer coming out of the shed floor
• 2 inch ball valve
• pool pump (with unions on both ends)
• cartridge filter (with unions on both ends)
• 2 inch check valve
• zinc anode
• inline chlorinator
• (with unions on both ends; might replace with SWG eventually)
• Jandy style 3-port valve
• two 2 inch to 1.5 inch reducers
• two 1.5 inch lines, each directly to one of the return inlets

My main questions are:

1. Do I only need one check valve?
2. If so, do I have it in the right location?
3. If I need more than one check valve, where do they go?
4. Is it unnecessary to have a Jandy valve splitting the flow to the two return lines? (could I just have a ball valve before I split the plumbing...meaning will I never have a reason to adjust the flow between the return or turn one off and have the other on?)
5. Should I have any valve allowing me to drain the system? (if I don't need the Jandy valve for the returns, I could put the valve some where in the system to allow the extra port to be a drain.)

Thanks!
- Rob

(below is a very rough layout of just the plumbing pipes running between the pad and the pool)

Pool survey overlay.png

• gerzak
• Jul 3, 2023
• pool plan pool plumbing

Rough location of 9x13 semi-inground pool, including suction and return lines

pool-backfilled.jpg

• gerzak
• Jul 3, 2023
• diy pool kit insulated semi-inground

Playgo 9x13 semi-ingrouind insulated pool after backfilling and retaining wall but before deck...

pool-plumbing-parts.jpg

• gerzak
• Jul 3, 2023
• pool filter variable speed pool pump

Assorted plumbing parts for my new 3500 gallon semi-inground pool

 

[HermanTX]

My main questions are:

1. Do I only need one check valve?
2. If so, do I have it in the right location?
3. If I need more than one check valve, where do they go?
4. Is it unnecessary to have a Jandy valve splitting the flow to the two return lines? (could I just have a ball valve before I split the plumbing...meaning will I never have a reason to adjust the flow between the return or turn one off and have the other on?)
5. Should I have any valve allowing me to drain the system? (if I don't need the Jandy valve for the returns, I could put the valve some where in the system to allow the extra port to be a drain.)

do not use the ball valve. On the inlet of the pump change that ball valve to a standard 2 way diverted valve. That ball valve will eventually leak or fail to rotate and the only way to repair is to cut it out and replace. But if you use a 2 way diverter valve they that is repairable if needed.

I see no reason for a check valve since the pump is below pool water level. Also, you only have a pump and filter. If you had a heater, you would want to have a check valve after it if you were using the table chlorinator.

Ensure those sweep elbows are sch 40 or 80. Do not use any pipework or fittings that are rated for DWV application only.

The 3 way valve valve that is before the connection to the return pipe is fine as you would not need to balance any flow between the 2 return pipes. You only need to 1 or the other open or preferably both open all the time. If the other pipe was for a water feature then it would make since to have a 2-way diverter valve on each line.

Suggest you create a drain line that bypasses the filter. So between the pump exit and the filter, install a tee. Then on the line that will become the drain line put a 2-way diverted valve. Also need to put a 2-way diverter valve between the tee and the filter inlet. So you would open the drain line diverter valve and close the filter diverter valve to pump water to drain.
The alternative would be to put a 3-way valve in place of the tee, (just ensure you install it properly) such that is full open during normal filter but can close the path to filter and then open path to drain line. You would still require the 2-way valve on the drain line.

When you create the line from the filter to the return, ensure there is sufficient straight pipe for the future SWCG. Shoot for 18-24 inches if possible. You do not need to install unions on your chlorinator now as it is not the same length of a future SWCG. Plus your SWCG will come with its own unions. When the time comes, just cut pipe on either side of the chlorinator and space out the SWCG for installation.

Install a relief valve and pressure gauge on top of the filter.

 

[gerzak]

Thanks, Herman. That is all super helpful. I wish I discovered this forum earlier!

I got impatient over the holiday weekend and went ahead and plumbed everything before I got your response to my questions (the family is anxiously waiting for the pool to be done with the hot weather we've been having).

Looking at your notes, I realize that I've made some mistakes. I'm prepared to reroute or replace anything I need to, and I'll get around to making some of the changes you suggested ASAP.

I started the pump yesterday, but every time I shut it off it drains down a bit and gets air in the system. All of the plumbing is lower than the waterline, and the plumbing goes underground to get from the pool to the shed where I have the equipment.

I don't see any leaks, but I'll go back and tighten all the threaded fittings in case the air is coming in through a coupling, a cap, or through the pressure gauge on the filter (which seemed like it went in way too easily, even with a bunch of teflon tape on the threads).

If not, here are a couple of my uneducated guesses as to where the problem is:

• the pipe from the pump to the filter is higher than the top of the filter. Is that a problem?
• the anode is at the top of the pipe going to the filter, so it's an obvious place for air to rise to.
• is there any issue with going underground and coming back up into the shed?
• The skimmer has a 1.5" outlet, but the pipe between the skimmer and the pump is all 2". Do I need a skimmer with a bigger outlet?
• From looking at the photos, is there any other red flag in how I've set things up?

(see photos below for reference)

I've done a ton of research, and I'm usually pretty good at figuring out technical issues, but I've struggled to feel confident that I'm doing any of this right. I'm comfortable with constructive criticism, so feel free to tell me how bad I may have screwed up.


One more thing to note: I realize that the shed Isn't the ideal place to put pool equipment, but i'll be doing a thorough job of adding waterproofing (sort of like a shower pan), adding a drain, and ventilating the building properly. I just wanted to make sure the plumbing was working properly first, since the pool is already full of water.

Thanks again for any help you can give!

plunge-pool-plumbing-pad.jpg

• gerzak
• Jul 7, 2023

I know there are some things wrong with this setup...that's why I'm here! :)
I also realize that...

plunge-pool-plumbing-3.jpg

• gerzak
• Jul 7, 2023

pool plumbing lines before adding support hangers

plunge-pool-plumbing-5.jpg

• gerzak
• Jul 7, 2023

plunge pool suction and return lines before backfilling; the pipes drop to about the level of...

plunge-pool-plumbing-1.jpg

• gerzak
• Jul 7, 2023

pool plumbing lines before adding support hangers

plunge-pool-plumbing-2.jpg

• gerzak
• Jul 7, 2023

pool plumbing lines before adding support hangers

 

[HermanTX]

I started the pump yesterday, but every time I shut it off it drains down a bit and gets air in the system. All of the plumbing is lower than the waterline, and the plumbing goes underground to get from the pool to the shed where I have the equipment.

Overall your plumbing work is excellent.
With regard to air leaks on suction side - always ensure the pump cap seal is well lubed and bump the cap tight with the palm of your hand when closing it. Also, there are 2 pump drain plugs - one under the basket and 1 under the impeller. Ensure those did not come loose.

The high loop may be an issue as on low speed the pipe is not being completely filled. Seeing the photo, you can either leave the pipe work as it is from the pump to the filter inlet and put a check valve before the pump. This would hold all the water falling back down when the pump turns off. Even though your pump is below water level, that loop is most likely trapping air. The alternative would be to reduce the height of pipework. My pipework from the pump to the filter, does not exceed the mid-point of the filter. So you could remove the ball valve from on top the pump exit and just make a short straight then a 90 deg turn to go around the filter. The easier solution may just be adding a check valve before the pump, if there is room.

I cannot see the drain line behind the filter. It appears to have a Tee fitting before it goes into the inlet of the filter.

The return side from the filter looks great. Really do not need a check valve after the filter (with the chlorinator) but it does not hurt. If you had an heater then definitely would need a check valve with a chlorinator. Appears it will be easy to install a SWCG in the future by removing the chlorinator.

The skimmer has a 1.5" outlet, but the pipe between the skimmer and the pump is all 2". Do I need a skimmer with a bigger outlet?

There are many pools with 1.5 inch pipe from the skimmer that only goes to 2 inch at the equipment pad. You are better off with the 2 inch over the longer length.

Overall it is a good job, be wary of the those ball valves as they tend to fail over time and you have to cut them out. Replace with a 2-way diverter valve.

 

[gerzak]

Thanks for the compliments! I did my best to figure out the ideal way to build this system, but I figured it would need at least a little bit of tweaking to get it just right. I'll make a couple modifications based on your suggestions and let you know how it goes.

 

[ajw22]

It looks like you use small hub DWV sweep 90's rather then large hub schedule 40 pressure rated 90s.

Read about the difference between DWV and Schedule 40 in PVC Repair - Further Reading

 

[gerzak]

Yes, I just realized that there was a difference between DWV and schedule 40 fittings after I got the whole thing built.

I had checked the pipe at the big box store, so I figured the fittings would be similarly rated—so many things to learn during this process!

The good thing is that I am running my pump at a very low speed (because the pool is only 3500 gallons and there are only a few pipes running to it), and there isn’t a single fitting that I won’t be able to get access to later if something fails. So I think I’ll be taking my chances for now, and I’ll plan to upgrade things in the near future.

 

[HermanTX]

Where is the best place to buy the correct pressure rated fittings anyway? They don’t carry any of them at the local big box stores.

HD, Lowe's & Ace Hardware all carry schedule 40 pipe and fittings in the plumbing section. It is separate from the DWV fittings. However, it is hard to find the long sweep elbows at those stores as they have the standard 90 deg elbows. You may want to try a plumbing supply store or online.

I have never found a pressure rating for the DWV fittings, there may be one but it would be very low. So be aware that you have fittings that could come loose or fracture.

 

[gerzak]

Yeah, I’ll definitely get around to replacing the pvc fittings soon. I’ll likely just order some online as I haven’t found any locally.

 

[rstarke]

Some additional things to think about should you replumb:

Try making the straight pipe going into the pump longer to improve the flow rate. Rule of thumb is 1" per 0.1 HP so for a 1.5 HP pump you would want 15" of straight pipe.

Don't use ball valves and make sure to not put any valves directly before or after the pump. Usually the valves have smaller diameters than the pipes and create turbulence in thewater and therefore reduce flow.

You can consider a check valve between the pump and the filter instead of a ball valve. It will also prevent flow back when cleaning the pump basket. It's usually cheaper and should not affect the flow as much as a valve.

The DWV is a big booboo but we are all here to learn and I've seen a couple of people doing it without trouble in the long run so fingers crossed.

If you decide to order fittings online double or triple check that you have the correct parts and sizes. I just wasted $90 in shipping costs because the online shop and I couldn't get it right and 3 packages were necessary to get all the correct parts *facepalm* (I needed Spears socket unions in 1.5")

 

[ajw22]

Try making the straight pipe going into the pump longer to improve the flow rate. Rule of thumb is 1" per 0.1 HP so for a 1.5 HP pump you would want 15" of straight pipe.

Pentair recommendation for straight pipe into the pump is 5xpipe diameter. 2" pipe = 10 inches straight pipe. 1.5" pipe - 7.5" straight pipe.



HP is not a factor in causing inlet turbulence. Although may people don't have the length of straight pipe and their pumps work fine.

Don't use ball valves and make sure to not put any valves directly before or after the pump. Usually the valves have smaller diameters than the pipes and create turbulence in thewater and therefore reduce flow.

The biggest reason not to use ball valves is they eventually stick and the handles break and are not repairable and need to be cut out to be replaced. Diverter valves can be rebuilt and last many years.

Any turbulence is a minor issue that is not measurable.

And with modern VS pumps rare usually run at low speeds where flow and turbulence is easily overcome..